1. Field of the Invention
The present invention relates to a tire forming system wherein three forming drums, i.e. a belt drum, a band drum and a shaping drum, are linearly arranged with reference to each other. Specifically, the present invention pertains to a tire forming system which can be applied to produce large- and medium-sized steel radial tires used for a trucks, buses or light vans, and small-sized radial tires used for passenger cars.
2. Description of the Related Art
A tire forming system is disclosed in Japanese Patent Application Laid-Open Publication No. 2-107,432, wherein a belt drum, a band drum and a shaping drum are linearly arranged with reference to each other. Such a tire forming system is used to prepare a green tire to be subsequently vulcanized for forming a product tire. In this instance, various members are supplied from outside onto the belt drum and the band drum via respective servers such that a belt-tread band is formed on the belt drum and a carcass band is formed on the band drum. Furthermore, the belt-tread band from the belt drum and the carcass band from the band drum are automatically transferred onto the shaping drum where they are automatically assembled with each other.
All of the above-mentioned operations associated with the shaping drum are performed automatically, without manual operation to be performed by operators. Still, however, the operators must be engaged with various manual operations while frequently moving back and forth between the remaining two drums, i.e., the belt drum and the band drum. Such manual operations include, among other things, guiding the front ends of various members from the respective servers to predetermined positions on the belt drum and the band drum, cutting the members as they have been wound around the respective drums, and subsequently joining the front and rear ends of the wound members.
As particularly shown in FIG. 3, the belt drum 01 and the band drum 02 are separately arranged on both sides of the shaping drum 03. Thus, the operator must move over a substantial distance between the belt drum 01 and the band drum 02 whenever bonding and joining the members. In the case of forming system for large-sized tires, for example, the distance between the two drums may amount to as long as approximately four meters. On the other hand, a recent development in the green tire formation technology resulted in a shortened cycle time required for forming a green tire. Thus, the total distance for an operator to move between the two drums per one working day has significantly increased. It is highly desirous to minimize the manual work load for the operators.
Moreover, since the belt drum 01 and the band drum 02 are separated from each other on both sides of the shaping drum 03, it is necessary to provide two transfer units, i.e., a belt transfer unit 04 and a band transfer unit 05. Such an arrangement is complex in structure, relatively expensive and less reliable in operation.